From 08a7f3fcd48003d233559dd9f56c31e6749c98f5 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <nathan@kernel.org>
Date: Tue, 22 Feb 2022 08:20:46 -0700
Subject: drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config()
Git-commit: 3b2f68f196a5b23c61777078f5c7d0d19626b5e4
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Clang warns:
drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
default:
^~~~~~~
drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
val |= LxPCR_YCEN;
^~~
drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
u32 val;
^
= 0
1 warning generated.
Use a return instead of break in the default case to fix the warning.
Add an error message so that this return is not silent, which could hide
issues in the future.
Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats")
Link: https://github.com/ClangBuiltLinux/linux/issues/1575
Acked-by: Yannick Fertre <yannick.fertre@foss.st.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Philippe Cornu <philippe.cornu@foss.st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220222152045.484610-1-nathan@kernel.org
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/stm/ltdc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 5eeb32c9c9ce..c9bc4ccb6d43 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -624,7 +624,8 @@ static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fm
break;
default:
/* RGB or not a YCbCr supported format */
- break;
+ DRM_ERROR("Unsupported pixel format: %u\n", drm_pix_fmt);
+ return;
}
/* Enable limited range */
--
2.38.1